The present invention is related to temperature measuring devices for taking the temperature of medical patients, and is more particularly related to cordless electronic thermometers.
Electronic thermometers have recently been developed to take the place of mercury thermometers for taking the temperature of medical patients. In many of these devices, the temperature sensing probe which is placed in contact with the patient, such as under the patient's tongue, must be continuously connected to a source of power and other electronic circuitry for converting an electrical parameter of the probe to a temperature reading. This is normally done by a long cord which is attached at one end to the temperature sensing probe, and at the other end to appropriate electronics.
U.S. Pat. No. 4,176,556 issued Dec. 4, 1979 to Takenaka for "Electronic Thermometer", discloses an electronic thermometer which utilizes a microprocessor, a bridge circuit containing a temperature responsive transducer, a charge and discharge circuit, and an interrupt signal generating circuit. A counted value corresponding to a reference temperature is added to a counted value corresponding to the time it takes a capacitor connected to the bridge circuit to discharge, and the result is converted to a temperature degree and displayed by the microprocessor.
Other patents of interest are: U.S. Pat. Nos. 3,348,415 issued Oct. 24, 1967 for "Temperature Measuring Device"; 3,851,528 issued Dec. 3, 1974 for "Electronic Thermometer"; 3,978,325 issued Aug. 31, 1976 for "Electronic Thermometer"; 4,008,617 issued Feb. 22, 1977 for "Electronic Thermometer and Method"; 4,022,063 issued May 10, 1977 for "Electromechanical Digital Thermometer"; and 4,371,271 issued Feb. 1, 1983 for "Electronic Thermometer".